TRENTON - Gov. Chris Christie's chief of staff says he was asked to look into the lane closures at the George Washington Bridge in December, but knew nothing of the scandal before that.

Kevin O'Dowd testified in front of the committee investigations into September's traffic jams on Monday.

O'Dowd described the order from the governor on Dec. 12. "He said, 'Kevin this bridge issue is still out there. All the noise about politics, political retribution. This is a major distraction. I need you to talk to BK and ask her if she had anything to do with closing the lanes at the bridge."

Just a few weeks later, an explosive email allegedly from Bridget Anne Kelly surfaced, claiming it was "time for some traffic problems in Fort Lee." Weeks later, Kelly was fired for lying to the governor. 

Lawmakers grilled O'Dowd for more than six hours trying to find out if he and other senior officials in the governor's office did their best to find out who was behind the lane closure scandal. O'Dowd says Kelly told him she had nothing to do with it.

O'Dowd says he found Kelly's response credible. "Bridget Kelly is someone I have worked with and known for years," he says. "Someone who I thought very highly of. Hardworking. Energetic. Loyal. Someone who I believed and trusted."

Christie's re-election campaign manager Bill Stepien was stripped of a promotion. Stepien sat in on Monday's hearing but left without speaking to reporters.

O'Dowd is Christie's choice to be the next state attorney general.